Mechanical and thermal properties of calcium carbonate‐filled PP/LLDPE composite

Abstract

Polymer blends typically are the most economical means to develop new resins for specific applications with the best cost/performance balance. In this paper, the mechanical properties, melting, glass transition, and crystallization behavoir of 80 phr polypropylene (PP) with varying weights of linear low density polyethylene (LLDPE) at 10, 20/ 20 wt % CaCO 3 , 30, 40, and 50 phr were studied. A variety of physical properties such as tensile strength, impact strength, and flexural strength of these blends were evaluated. The compatibility of these composite was examined by differential scanning calorimetry (DSC) to estimate T m and T c , and by dynamic mechanical analysis (DMA) to estimate T g . The fractographic analysis of these blends was examined by scanning electron microscopy (SEM). It has been confirmed that increasing the LLDPE content trends to decreases the tensile strength and flexural strength. However, increasing the LLDPE content led to increases in the impact strength of PP/LLDPE blends. It was also found that up to 40 phr the corresponding melting point (T m ) was not effected with increasing LLDPE content. Each compound has more than one T g , which was informed that there is a brittle-ductile transition in fracture nature of these blends, the amount of material plastically deformed on the failure surface seems to increase with the increasing the LLDPE content. And PP/LLDPE blends at temperature (23 C) showed a ductile fracture mode characterized by the co-existence of a shear yielding process; whereas at lower temperature (À20 C) the fractured surfaces of specimens appear completely brittle. The specimens broke into two pieces with no evidence of stress whitening, permanent macroscopic deformation or yielding.

The investigation of alumina nanoparticles’ effects on the mechanical and thermal properties of HDPE/rPET/MAPE blends

“…Since the production of the cavity is associated with energy consumption, the impact energy of the samples rises. Of course, this mechanism is highly dependent on the geometry of particles and has been reported by researchers for spherical particles such as calcium carbonate [24,25]. On the other hand, an increase in the content of nanoparticles up to 5 wt% has reduced the impact strength due to the agglomeration of nanoparticles.…”

Mechanical enhancement of zirconia reinforced polyimine nanocomposites

“…Over recent decades, polymeric nanocomposites with nanoscale fillers embedded in polymer matrices have become the focus of tremendous research to meet higher performance requirements and processing demands . These nanocomposites have demonstrated significant property improvements when compared with the polymer matrices or conventional composites, combining the advantages of polymer and nanoparticle fillers . On the one hand, the compressive and flexural mechanical properties of polymeric nanocomposites can be dramatically increased by the low‐concentration nanoparticle fillers .…”

“…[1][2][3] These nanocomposites have demonstrated significant property improvements when compared with the polymer matrices or conventional composites, combining the advantages of polymer and nanoparticle fillers. [4][5][6] On the one hand, the compressive and flexural mechanical properties of polymeric nanocomposites can be dramatically increased by the low-concentration nanoparticle fillers. 2,[7][8][9] On the other hand, compared with microscale fillers, nanoparticles possess much higher specific surface area (surface to volume ratios), which afford more surface contact and stronger interaction between the filler and the matrix, resulting in better property enhancement.…”

Relationship between the morphology and interfacial tension of polypropylene and ethylene propylene diene monomer blends: The effect of repetitive extrusion

“…The addition of rubber reinforces its notch sensitivity and impact toughness. In this regard, the morphological, mechanical, and thermal properties of polypropylene (PP) blends with various polymers or fillers have been studied, including ethylene propylene diene monomer (EPDM) rubber,8–11 polyurethane elastomer,12 natural rubber,13 styrene‐butadiene rubber,14 poly(acrylonitrile‐butadiene‐styrene),15–17 polyethylene,18–22 and organoclay 22–26…”